Yes, in certain circumstances. However, it involves a special process and there would be a charge involved. If the cylinder and keys are registered, you would need to approach the ASSA Security Centre which supplied them and holds the records. Standard differ cylinders can be re-keyed by any ASSA Security Centre (if in doubt, please contact our Systems Department with the reference number stamped on the cylinder and we can advise which stockist can carry out the job).
The re-keying operation involves carefully drilling out the cylinder plugs, removing the pins and inserting new ones, then updating the key system records and cutting new keys. Please be warned that not every cylinder design can be re-worked in this way; the Security Centre can advise if it will be possible in your case.
Of course, reprogramming an ASSA CLIQ electromechanical cylinder to accept a different key is simplicity itself.